CVE-2025-39721: Linux kernel · crypto: qat – flush misc workqueue during device shutdown
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in fe546f5c50fc474daca6bee72caa7ab68a74c33d : patch Linux kernel soon.
Data as of 5 Nov 2026, 21:48 UTC
Rated High by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-05.
- Patch
- Available – fixed in fe546f5c50fc474daca6bee72caa7ab68a74c33d, fa4c14a82747886d333d8baef0d26da86ba1ccf7, e59a52e429e13df3feb34f4853a8e36d121ed937 +2
Exploitation evidence
Disclosed: evidence found.
CVE published 5 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available and has been applied in specific commits to the Linux kernel. The remediation involves flushing the misc workqueue during device shutdown to ensure all pending work completes before the driver unloads. Users should update to a Linux kernel version that includes these fixes. No additional mitigation steps are indicated.
Description
A use-after-free vulnerability in the Linux kernel's QAT driver can cause a kernel crash when repeatedly loading and unloading a device-specific QAT driver. The issue arises because a shared workqueue is not flushed during device shutdown, allowing deferred routines to access freed memory. The fix involves flushing the misc workqueue during device shutdown to ensure all pending work completes before unloading the driver.
References
- git.kernel.org/stable/c/fa4c14a82747886d333d8baef0d26da86ba1ccf7 (opens in a new tab)
- git.kernel.org/stable/c/5858448a6c65d8ee3f8600570d3ce19febcb33be (opens in a new tab)
- git.kernel.org/stable/c/fe546f5c50fc474daca6bee72caa7ab68a74c33d (opens in a new tab)
- git.kernel.org/stable/c/e59a52e429e13df3feb34f4853a8e36d121ed937 (opens in a new tab)
- git.kernel.org/stable/c/3d4df408ba9bad2b205c7fb8afc1836a6a4ca88a (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)